The present invention relates to a method and system for modeling an inflatable supplemental restraint device for a vehicle. Such devices include, without limitation, a driver side airbag (DAB), passenger side airbag (PAB), a side impact airbag (SAB), and a curtain airbag (CAB).
Modeling the contact between the occupant of a vehicle and a supplemental restraint device such as a steering wheel airbag, or side airbag is an important aspect of automotive crash simulation. In order to predict the contact between a vehicle's occupant and an airbag with precision, the airbag must be modeled in terms of the correct configuration, as well as the gas pressure within the airbag and the airbag's trajectory and deployment force. It is known that different bag-folding patterns may significantly influence the character of the airbag's deployment and enhance the interaction between the airbag and the occupant. As a result, a correctly folded airbag finite element model is an important step in assuring proper contact of the airbag and vehicle occupant during a finite element simulation. In addition, the final shape of the airbag is another important factor affecting occupant kinematics and impact characteristics, and it has thus been desirable to use a finite element model of the folded airbag derived directly from its fully deployed shape. However, available airbag folding tools create finite element models of folded airbags from flattened airbags. Therefore, a method has been needed to transfer a 3D airbag model into a 2D model to permit creation of a robust folded airbag model.
The present invention provides a system and method for creating a finite element model of a folded airbag from a finite element model of a fully deployed airbag. By using a finite element explicit tool such as Radioss, LS-DYNA, MADYMO, or PAM-CRASH to simulate the real world airbag folding procedure as the airbag is folded, assembled and packaged, a robust FEA model may be constructed.